There is a longstanding need in the area of architectural window frames for a window frame which has a curved or rounded top portion. In the past, wooden frames with rounded tops were fabricated using a plurality of individual segments which are connected together and which are then machined to form a curved configuration.
Conventional round top vinyl windows make use of the thermoplastic properties of polyvinyl chloride window lineals or framing materials. The construction of a conventional round top vinyl window involves the heating of the window lineals to the point where they are pliable and forming them into the desired round top shape. This process is slow and requires sophisticated expensive machinery to avoid excessive distortion of the lineals.